Salmonella in free living terrestrial and aquatic turtles.

Detection of Salmonella in pet turtles has been the focus of extensive research, but its incidence in free living turtles is not well known. The aim of this study was to evaluate the incidence of Salmonella in terrestrial and aquatic species of chelonians inhabiting a National Park in southwestern Spain. Individuals of the terrestrial tortoise Testudo graeca (n = 16) and the aquatic turtles Emys orbicularis (n = 26) and Mauremys leprosa (n = 50) were investigated. Maximum incidence of Salmonella was recorded in the terrestrial species (100%). In contrast, the incidence of infected animals was low in the aquatic species, 12% in M. leprosa and 15.4% in E. orbicularis. Five serotypes of Salmonella belonging to subspecies enterica (I) and salamae (II) were identified. All serotypes were found in the terrestrial species, and three in the aquatic ones, suggesting that wild terrestrial chelonians are important reservoirs of Salmonella in our study area. Cloacal transmission during mating is the most probable mode of transmission among individuals.